The possibility of future dementia isn’t just a matter of fate. Modifiable dementia risk factors are those that can be reduced — and for which you can make positive changes to stave off mental decline in your own life.
It’s not too surprising that boxing careers or decades of heavy drinking raise the likelihood of developing dementia. But hearing loss in middle age, social isolation and even air pollution are significant contributors, too.
Genetics and dementia family history are beyond your control, and other influences are too complex to confront on an individual level. Social determinants of health, environmental factors and widespread health inequities represent larger challenges for change.
Even so, you can help yourself by incorporating health and lifestyle practices that mitigate against known dementia risk factors now.
Key Risk Factors
Modifying 12 risk factors could delay or prevent up to 40% of dementia cases, according to an evidence analysis in the updated “Dementia Prevention, Intervention, and Care: 2020 Report of the Lancet Commission.”
These are key risk factors — many arising later in life, but some sooner — for dementia:
— Less education in early life.
— Hearing loss in midlife.
— Traumatic brain injury.
— High blood pressure.
— Alcohol (moderate to high weekly use).
— Physical inactivity.
— Air pollution.
Excessive alcohol consumption, head injury and air pollution are the risk factors most recently identified in the Lancet Commission’s evidence evaluation. Hearing, education and smoking are the three biggest risk factors.
Education comprises aspects such as literacy, schooling and more. “It appears that it’s not just education at a young age,” says Dr. Gill Livingston, who heads the report committee. “Doing things to stimulate your brain as you get older also makes a difference.” For instance, she says, being involved in an occupation that keeps you mentally alert seems to be protective of your brain.
“Smoking is the next one that makes a difference at a population level,” says Livingston, who is a consultant psychiatrist and professor of psychiatry of older people with University College London. “The good news about smoking is even reducing smoking when you’re older seems to begin to reduce your rate of having dementia.”
Hearing Loss in Middle Age
Inability to hear now can affect your dementia risk later. “What people often don’t know, and I didn’t know until we started doing all of this work, is that the biggest potentially modifiable risk factor for dementia is hearing impairment in midlife,” Livingston says. “If you know people 15 to 20 years before the age where they were likely to develop dementia, those who have hearing impairment have twice the risk of developing dementia than those who don’t.”
To change that dynamic, other research groups have been doing important work to prove how much difference hearing aids make, Livingston says: “And it seems that if you use hearing aids, then your risk drops down to the rest of the population.”
Among nearly 115,000 people older than 66 newly diagnosed with hearing loss, getting a hearing aid reduced their risk of being diagnosed with dementia or depression — a dementia risk factor in itself — over the next three years, in a University of Michigan study published Sept. 4, 2019, in the Journal of the American Geriatrics Society.
[See: Best Foods for Brain Health.]
Traumatic Brain Injury
Research has been building on the multiple harms of head trauma by causes ranging from wartime blast injuries to sports-related concussions or multiple impacts. Evidence increasingly points to dementia as another potential consequence, and risk increases with each episode, according to a recent study.
“We found that a history of a single prior head injury was associated with a 1.25 times increased risk of dementia — and a history of two or more prior head injuries was associated with over two times increased risk of dementia compared to individuals without a head injury,” says Dr. Andrea Schneider, a physician with Penn Medicine and an assistant professor in the department of neurology at University of Pennsylvania Perelman School of Medicine.
The evidence encompassed 25 years’ worth of data on more than 14,000 participants from a long-term study on the risk of atherosclerosis. Researchers interviewed participants and reviewed their hospital records related to head injuries. In particular, head injury after age 45 in was associated with an increased risk of developing dementia, in the study published in March 2021 in the journal Alzheimer’s & Dementia.
The findings suggest that “the number of head injuries sustained matters, and there is an important need for future research focused on prevention and intervention strategies aimed at reducing dementia after head injury,” Schneider says.
Genetics or family history of dementia and aging are among major risk factors for dementia that cannot be modified, Schneider notes. But, she adds, “One common misconception is that dementia is inevitable with aging — this is not true. Dementia is not a normal part of aging; however, the risk of dementia does increase with age.”
Although a limited amount of drinking may be good for the brain, even moderate alcohol use can raise the risk of dementia.
“Alcohol does make a difference,” Livingston says. “Drinking a little, seems to be, if anything, protective. But drinking a lot, even what people might call social drinking, makes you more likely to develop dementia.” The risk of young-onset dementia — dementia that develops before age 65 — in particular has been connected with significant alcohol use.
In general, consuming what amounts to more than 14 servings (in U.S. measurements) of alcohol weekly increases dementia risk, Livingston says. “That number is quite easy to (reach) if you have a drink or two with dinner or socialize,” she notes. “It’s an amount you could easily drink without being drunk or without being dependent. So go out and have a drink some nights, but not every night.”
Managing your blood pressure — whether through lifestyle measures such as weight loss and exercise, medication or a combination — can help prevent high blood pressure from becoming a dementia risk factor. Blood pressure is among multiple factors in brain health for primary care providers to address with patients, according to a scientific statement from the American Heart Association/American Stroke Association published in June 2021 issue of the journal Stroke.
“It’s keeping your blood pressure down,” says Ronald Lazar, director of the Evelyn F. McKnight Brain Institute at the University of Alabama at Birmingham School of Medicine and a statement author. “It is keeping your cholesterol under control. It is eating properly; a good diet. It’s making sure that you don’t get overweight, sleeping properly, keeping yourself socially engaged with the rest of the world. It’s managing your mood state, so that if you’re depressed, it’s being addressed.”
Reducing inflammation is a common thread. “In many ways, what a lot of these lifestyle behaviors and risk-factor management do is minimize inflammation,” Lazar says. “Inflammation in the body, for different kinds of reasons, can influence inflammation in the brain, as well as directly causing inflammation in the brain by itself.” The connection between the gut and brain health is increasingly recognized, he adds, and with it, the need to minimize gut inflammation.
“In terms of a single lifestyle practice, exercise benefits all others,” Lazar says. “It’s probably first among equals.” Although aerobic exercise is the best in this context, he says, resistance training also has supporting evidence.
As far as a healthy diet, “The thing is to eat appropriately and avoid high fats,” Lazar says. “You really don’t want to create atherosclerosis in any part of the body, including the brain.”
Balanced diets such as MIND, Mediterranean diet and DASH are among eating plans that cover those bases. The MIND diet was created specifically to reduce dementia risk, and recent evidence is encouraging.
Social Determinants of Dementia
Air pollution is a recently identified dementia risk factor that isn’t so easy to escape. Stress is another complex problem that may indirectly affect dementia risk, making stress reduction important.
“There’s pretty good evidence now that stress causes inflammation,” Lazar says. “So, disparate communities, disparate populations have the highest risk for stroke and dementia. One reason that’s the case is because of the stress that often exists in individuals who are struggling to make ends meet, have family burdens and the environments in which they live create stress as well. This is one of the impacts of adverse social determinants. And stress is not good for the body and, in turn, not good for the brain.”
Steps to Stave Off Dementia
Depending on your individual circumstance and any medical conditions, you can lower your risk of developing dementia — or possibly delay dementia onset for years — by incorporating these brain-friendly practices:
— Controlling your blood pressure.
— Having your hearing checked.
— Using hearing aids if needed.
— Managing your blood sugar if you have diabetes.
— Avoiding head injury and using helmets for protection.
— Exercising regularly.
— Social interaction — seeing other people.
— Ongoing education and mental stimulation.
— Eating a healthy diet.
— Stress reduction.
— Maintaining a healthy weight.
Your primary care provider should be talking with you about promoting lifelong brain health. “We want to create more mindfulness in the conversation between patients and their providers,” Lazar says. “And if the providers don’t bring it forth, then patients should serve as their own advocates and start asking questions.”
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